Acoustic micro electromechanical system (MEMS) transducers, such as ultrasonic transducers, are typically more efficient than traditional transducers. However, due to their small size, MEMS transducers have lower effective output power, lower sensitivity and/or broader (less focused) radiation patterns.
Radiation patterns of acoustic MEMS transducers and other miniature ultrasonic transducers may be manipulated by grouping the transducers into arrays, separated by predetermined distances, in order to provide a desired pattern. By controlling the separation and size of the array elements, as well as the phase among them, the acoustic radiation pattern may be focused or collimated, and also steered. However, the spacing among multiple transducers is limited by the physical size of each transducer. Further, the use of multiple transducers, possibly having different sizes, increases costs and raises potential compatibility and synchronization issues.